Galvanoplastic process and product.



M. IVI. MERRITT.

PLASTIC PROCESS AN LlcATloN FILED uw@` n PRODUCT.

Patented Oct. 22, 1918.

GALvANo llO nein' crans ramen ricerca.

MATTHEW MERRITT, vOE SOUTH MIDDLETON, MASSACHUSETTS, ASSIGN OR T0 COPPER PRODUCTS COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

GALVAN OPLASTIC PROCESS PRODUCT.

Patenten oet. ae, rais.

Original application led November 2, 1917, Serial No. 199,810. Divided and this application led December 8, 1917. Serial No. 206,293.

To ali wiz/om t may concern.'

Be it known that I, MATTHEW M. MERRITT, a citizen of the United States, and a resident of South Middleton, county of Essex, Com-v monwealth of Massachusetts, have invented kan Improvement in Galvanoplastic Processes and Products A, of which the following description', in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention pertains to improvements in galvano plastic processes and products, but more particularly, though not exclusively, to the manufacture of articles such as manifolds for internal combustion engines` such as aeroplane engines.

This application isa divisional of my copending application, Serial No. 199,810, filed November 2, 1917.

In the drawings, which show one form of an illustrative embodiment of my invention: Figure 1 shows a manifold; and

Fig. 2 is a diagrammatic section therethrough on the line 2 2 of Fig. 1.

Great difliculty has been experienced in constructing manifolds for aeroplane engines of the requisite light weight which are strong enough to withstand the constant and excessive vibrations occasioned by the operation of the engine. Such manifolds are very likely to develop cracks, particularly adjacent the bent-portions thereof. It has heretofore been attempted to manufacture such manifolds by the electrolytic deposit of copper on cathodes of metal fusible at a low temperature, and on cathodes of wax painted with graphite or other `electrically conductive material, the core being melted out after the electrolytic deposit. Manifolds made by the usual methods, above-described, have proved unsatisfactory because of brittleness and coarseness of texture of the deposited metal, this brittleness being accentuated at points adjacentX curved portions of the deposit. l

I have found that the deposits made as before described are rendered more uniform in quality by intermittent immersion of the cathode, as by attaching the same to a revolving wheel partially immersed in the electrolyte so that the entire cathode or a considerable portion thereof, preferably at least one-half, is only intermittently im-l mersed in the electrolyte. This aspect of my invention is not claimed prised in the subject matter of a copending application Serial No. 247,966, filed August 2, 1918. vWhile the intermittent immersion improves the texture of the deposited metal, electrolytic deposits made on metallic cathodes having low melting points are, as heretoforermade, likely to be rough and brittle.

I believe this to be due to the tendency of certain ingredients of theV fusible metal, which is usually an alloy 'of lead, to be attacked by the electrolyte, and in some instances to be disassociated into negative ions traveling from the cathode to the anode.

Where, on the other hand, the-cathode is formed of non-conductive material removable by fusion, by a solvent, or otherwise, and the surface of which is coated with an electrically conductive paint, such as graphite, bronze powder andthe like, the deposited copper, as heretofore practised, has been brittle and of slighttensile strength. As stated in my co-pending application, liled herewith, I believe this to be due to the comparatively coarse texture of the conductive coating which is necessarily full of interstices as compared with cast, rolled, or electrolytically deposited metal. The lunevenness of attraction exerted by this surfacing of the cathode results in combining the deposited metal in relatively coarse crystalline formation, which renders it brittle and of slight tensile strength. A

I have found that the deleterious effects of a cathode composed of metal having a low fusing-point may be minimized by coating the metal with a film of a foreign substance such as grease, and that if a layer of copper, preferably relatively thin, be electrolytically deposited subsequent to the application of the grease and the surface 0f this metal treated with mercuryor mercury amalgam, that subsequent electrolytic deposits on the mercury amalgamated surface will be of fine texture and of great tensile strength, the brittleness being greatly reduced if not eliminated.

-If desired, the structure may be laminated by the occasional interruption of electrolytic deposit and the application to the surface of the deposited metal of either a film of grease or a film of mercury amalgam.

Where it is necessary or desirable to utilize a non-metallic cathode Sllh as Wax 0l' herein being comany electrically non-conductive material removable by a solvent or otherwise, the same being coated with a aint of electrically conductive material, I ave found it of great advantage to deposit a, relatively thin sheet of copper or other metal on the'electrically conductive surface, mercury and to continue the electrolytic deposit on the amalgamated surface, the second deposit being very fine-grained and of relatively high' tensile strength compared with the initial deposit, and the initial deposit being improved in these respects by the comany substance capable of forming a film of' electrically non-conductive material over the surface on which the metal is to be deposited.

After electro-deposition the core of the cathode may be removed by fusion, by burning, by the use of a solvent or any other suitable method.

I have utilized the word galvanoplastic in its broader sense to include any electrolytic processes in which the entire cathode or any portion thereof is removed subsequentv to electrodeposition.

It is obvio'us that the cathode may, if desired, be exterior to the surface thereof on which metal is to be deposited, and that for v some purposes my invention may be useful in connection with galvanoplastic processes 1n which the cathode can be withdrawn without change in the structure thereof.

While I have shown and described one embodiment of my invention and one method of practising the same, it will be understood that major changes may be made, both in the product and the method of producing the to treat this surface with v same, without departing from the scope of my invention, which following claims.

Claims:

1. The method of forming galvanoplastic products which comprises applying to the surface of a removable, electrically non-conductive mold orcore a layer of electrically conductive substance, electrolytically depositing a layer of metal thereon, applying a foreign'substance of relativelylow tensile strength to the surface of said initiallayer of electrolytically deposited metal, continuing electro-deposition to provide a second layer of deposited metal separated from the first by said foreign substance, and subsequently removing the said mold or core.

2. The galvanoplastic process which comprises applying to the surface of a non-conductive mold or core an electrically conductive layer, electrolytically depositing a layer of metal thereon, amalgamating with mercury the surface of the deposited layer, electrolytically depositing a second coatin of metal on the amalgamated surface, and subsequently removing the mold or core.

3. The galvanoplastic process which comprises applying to the surface'of a nonconductive mold or core an electrically conductive coating, velectrolytically depositing a comparatively coarse-grained layer of copper on said conductive layer, amalgamating with mercury the surface ofv said relatively coarse-grained layer of copper, subsequently electrolytically depositing a second layer of copper, whereby said second layer of copper, partaking of the fine texture of the amalgamated surface, may be of i'ine grain and of relatively greater strengthl than the initial layer of copper, and subsequently removing the mold or core.

4. The galvanoplastic process which comprises depositing on the surface of a mold or core successive layers of metal separated by.

foreign substance of relatively low tensile strength, whereby successive laminations of metallic layers' 'are provided, and subsequently removing the mold or core.

In testimony whereof, I have signed my name to this specification.

- MATTHEW M. MERRITT.

is lbest defined in the l 

